Cleaning arrangement for electrode housing



1955 A. u. wAsTvlND ET AL 2,720,551

CLEANING ARRANGEMENT FOR ELECTRODE HOUSING Filed Sept. 6, 1951 3 Sheets-Sheet 1 hwdon/ Oct. 11, 1955 A. u. WASTVIND ETAL 2,720,551

CLEANING ARRANGEMENT FOR ELECTRODE HOUSING Filed Sept. 6, 1951 3 Sheets-Sheet 2 .6 2622* zzw zzr 2 W W t- 1955 A. u. wAs'rvlNo ETAL 2,

CLEANING ARRANGEMENT FOR ELECTRODE HOUSING Filed Sept. 6. 1951 3 Sheets-Sheet 3 United States Patent CLEANING ARRANGEMENT FOR ELECTRODE HOUSING Allan Uno Wiistvind, Bromma, and John Helge Lindbergh, Sundbyberg, Sweden, assignors to AB Svenska Flaktfabriken, Stockholm, Sweden, a corporation of Sweden Application September 6, 1951, Serial No. 245,294 Claims priority, application Sweden September 11, 1950 3 Claims. (Cl. 174-31) This invention relates to an arrangement in electrofilters provided with an electrode system centrally supported by the high tension insulator of an iron support.

The insulators belonging to electro-filters easily become dirty on the gas side due to impurities in the gas. In order to avoid the risk of breakdown these impurities must be wiped away before they are of such an extent that creeping currents and breakdown appear. In known constructions of electro-filters such cleaning cannot take place without disconnecting the filter which will cause interruption in operation. If the gases are noxious or explosive it will be necessary to exhaust the gases by means of air before opening the casing of the electrostatic filter. In like manner the filter, if normally used at high temperature, must also be disconnected until the filter has become cool. Cleaning involves therefore relatively long periods of interruptions in running. This, of course, has a very disturbing effect upon the cleansing plant in which the filter is placed. Furthermore this will be expensive as cleaned gas will be lost during disconnection periods or in de-aerating before the start. Possibly the filtering de vice must be duplicated having regard to the necessary cleaning of procelain, viz. in such cases when a long period of interruption in running, caused by the fact that the filter must first be cooled down and then heated again after cleaning, cannot be allowed owing to technical reasons.

The above mentioned disadvantages are eliminated by the present invention and the cleaning time reduced to a minimum. The invention involves the possibility of removing the poreclain insulator from the filter for cleaning which thus can be treated without the exhausting of gas and the cooling down which takes time. The invention is principally characterized in that the insulator is placed in a high tension chamber and formed as a tube resting on the filter roof and supporting a supporting plate with fastening means for the iron support which is enclosed in a displaceable tube" and a plate supported by this tube, both of which form together with the insulator a closed space of the filter chamber after displacement of the plate to contact with the ceiling of the filter, a duct leading to said space for supplying pure gas, and that one or more closable openings are made in the supporting plate close to the inside of the insulating tube. According to a modified construction a tube wall fastened to the ceiling of the filter is mounted in the space between the insulator and the tube surrounding the iron support and a duct is connected to the space between said tube and tube wall for supplying pure gas.

The invention is more fully described in the following with reference to the accompanying drawings, in which:

Figs. 1 to 3 show respectively three embodiments of the invention, and,

Fig. 4 shows an operating tool for use with the embodiments of Figs. 1 and 2.

In Figure 1 an iron support of the electrode system (not shown) is designated 1. The iron support is enclosed in a tube 2 and a plate 3 fitted to the lower end of the tube and at right angles to the same, said plate being provided with a flange 4 at its periphery. The iron support is supported by a fastening device 11 and can be raised or lowered by aid of the nut 12. The fastening device rests upon a supporting plate 10 which is in turn supported by the tubular insulator 7. The insulator rests on the roof of the filter 6 in the channels 17, and affords suspension of the rod support 1 through an opening defined by a flange 5 in the roof of the filter 6. A tube wall designated 8 is located between the insulator 7 and the adjacent tube 2 enclosing the iron support 1. A shutter and the corresponding opening in the supporting plate are designated 9.v The shutter is designated 9 in opened position. The high tension chamber surrounding the insulator is designated 16, and 15 shows diagrammatically a gas cleansing duct connected to a gas cleansing container (not shown). 13 designates the flanged ends of the tube 2, by means of which the tube rests upon the packing 14.

With the device described above the cleaning of the insulator 7 is carried out in the following manner. The electro-filter is first disconnected then the tube 2 and the plate 3 are raised for example by a tool indicated generally at 20 in Fig. 4 to such a height that the flange 4 of the plate makes tight contact with the lower side of the filter roof and closes off the opening defined by the flange 5. The shutter 9 is thereafter opened and cleaning and inspection of the insulator can take place immediately without losses of time for exhausting of gas or cooling down. Several shutters may be fitted along the periphery of the insulator. As soon as the plate 3 is lowered and the shutter 9 is closed again and the small quantity of gas it necessary is replaced by inert gas in the duct the filter is once more prepared for use. This inert gas is supplied through the air cleansing duct 15 which normally functions during running for supplying pure gas at a certain excess pressure to prevent impure gas from forcing up the insulator. The disadvantages of the insulator becoming dirty are hereby considerably limited and the period between necessary inspections and cleaning of the insulator will thereby be extended. This involves in turn economical advantages in operation.

Figure 2 shows a modified construction of the device. The elements corresponding to those of Figure l are provided with the same reference numerals. The differences between the two constructions illustrated are that in Fig. 2

the tubular wall 8 which corresponds to the wall 8 in Fig. l is made an integral part of the roof member 6 and projects therebelow, while the plate 3a which is mounted at the lower end of the sleeve 2 is bowl shaped. The embodiment shown in Figure 2 involves a simplification of the device as a small diameter of the porcelain is only necessary.

A construction may be employed in which the closing plate is normally situated immediately under the supporting plate and before cleaning of the insulator is lowered into tight contact with the roof of the filter. This is shown in Fig. 3 wherein a plate 3b is removably secured by bolts 21 against the bottom of a supporting plate 9b which rests on the porcelain insulator 7 similarly to the plate 9 in the previous embodiments. A handle 22 is adapted to be engaged with the plate 3b to afford lowering of the plate when cleaning the insulator. The plate is lowered by disengaging the bolts 21 and dropping the plate 3b against the roof over the opening therein. A gas cleansing duct similar to the duct 15 may be connected in the plate 3b if desired. It is noted that the plate 9b is provided with apertures for obtaining access to the interior of the porcelain insulator 7 when the plate 3b is engaged against the roof 6.

I claim:

1. An electrostatic filter construction comprising a main casing roof member having an opening therethrough, a

support for a discharge electrode system comprising a tubular insulator mounted upon said roof member concentrically of said opening, a closure member overlying said tubular insulatorand having at least one opening therein for inspection and cleanning the inside of said insulator, a rod support constituting an electrical conductor extending coaxially of the insulator and through the opening of the roof member, means supporting said rod support from the closure member coaxially of the tubular insulator, a plate generally parallel to said roof member surrounding the rod support and movable longitudinally thereof, said plate being normally positioned in spaced relation to the roof member in registry with the opening through the latter and operable to close the opening when said plate is moved longitudinally of the rod support thereby closing-ofi' the space within the tubular insulator, and means to supply gaseous fluid under pressure to said space.

2. Apparatus as claimed in claim 1 wherein a tubular wall member is positioned intermediate the insulator and the sleeve and is connected at one end to the roof member adjacent the opening therein.

3. Apparatus as claimed in claim 2 wherein the tubular wall member projects from the roof member at the opposite side thereof from the insulator.

References Cited in the file of this patent UNITED STATES PATENTS 

